This application claims the benefit of Japanese Patent Application No. 2004-156382 filed May 26, 2004, which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to stacking-type, multi-flow, heat exchangers, each comprising heat transfer tubes and fins, which are stacked alternately, and an end plate provided at an outermost position, which is provided with inlet and outlet pipes. Further, the invention relates to methods for manufacturing such heat exchangers. More specifically, the present invention relates to a structure of a pipe connection portion of a stacking-type, multi-flow, heat exchanger suitable as a heat exchanger for use in an air conditioning system, in particular, for vehicles.
2. Description of Related Art
Stacking-type, multi-flow, heat exchangers having alternately stacked heat transfer tubes and fins, and an end plate with inlet and outlet pipes provided at an outermost position in the stacking direction, are known, for example, as disclosed in Japanese Patent Application No. JP-A-2001-241881, which is incorporated herein by reference. In such a heat exchanger, a plate for pipe connection is connected to the end plate, and inlet and outlet pipes are inserted into holes formed through the plate for pipe connections.
However, in stacking-type, multi-flow, heat exchangers, such as a heat exchanger disclosed in Japanese Patent Application No. JP-A-2001-241881, because it is necessary to form a raised or elongated portion or portions on the plate for pipe connection, a plate having a sufficiently raised or elongated portion or portions is required for forming the plate for pipe connection. In particular, if a dimension of the plate in a thickness direction of the heat exchanger (e.g., an air flow direction) is not ensured, forming the raised or elongated portion or portions may become difficult. Therefore, because of the required plate size, the size and the weight of the entire heat exchanger may increase.
Further, such a heat exchanger is manufactured by brazing temporarily assembled parts simultaneously in a furnace. Because a raised or elongated portion(s) generally does(do) not have a precise dimension, it is necessary to interpose a separate member made of a brazing material, for example, a ring-like brazing material, between the raised or elongated portion(s) and a pipe(s) inserted thereinto, in order to achieve a properly brazed connection. When the raised or elongated portions and the inlet and outlet pipes are brazed to each other via a separate member of brazing material positioned therebetween, if the brazing-material member shifts from its proper position during brazing and other stages, the brazing quality may be reduced.